1. Technical Field
The invention disclosed broadly relates to data processor control of telephone switching and more particularly relates to telephone communication path switching in a personal computer system.
2. Background Art
The problem of selectively connecting a first plurality of telephone lines to a second plurality of telephone lines has been achieved in the prior art by means of complex gang switching arrangements which simultaneously connect both the transmit and the receive line of a particular communications session. An example of this prior art is U.S. Pat. No. 4,075,608 to Koenig, which shows a plural stage switch matrix under the control of a minicomputer. The plural stages of the matrix are gang switched so that both the transmit and the receive path for a particular telephone link, are simultaneously switched along the same path. As telephone technology has advanced, a wide variety of auxiliary telephone signal processing elements has evolved, for example call progress monitors which monitor the sequence of trunk connections by means of the characteristic signal tones transmitted over the link. In addition, dual tone multifrequency transmitters and receivers enable the user to transmit call establishment signals over the network. Other devices such as automatic dialers and answer tone detectors enable the automatic establishment of calls between unattended stations. In such a diverse telephonic network, where some elements are limited to transmission whereas other elements are limited to reception of signals, it is inefficient to simultaneously gang switch both the transmit and the receive paths for a particular telephonic session, and indeed such simultaneous gang switching as is practiced by the prior art limits the flexibility in the connectivity of a modern telephone system.